The following sources of information are known:
1. European patent No. 0434268 publ. 26.06.91 PA1 2. U.S. Pat. No. 4,761,653, publ. 02.08.88 PA1 3. U.S. Pat. No. 4,833,482, publ. 23.05.89 PA1 4. European patent No. 0543519, publ. 25.05.93 PA1 5. Patent of Great Britain No. 2230902, publ. 23.02.90 PA1 6. European patent No. 0427479, publ. 15.05.91 PA1 7. U.S. Pat. No. 4,792,810, publ. 22.06.86
There are microstrip antennas for receiving two polarizations, with a dielectric sheet, on one side of which screen (grounding) metallization is arranged. On the other side, there are radiating elements and feeding systems for radiators of both polarizations.
Advantages of such antennas: simple construction--power circuits for radiators of both polarizations arranged on one surfaces of a dielectric sheet without intersection.
The main drawback of such antennas: big losses in power circuits. Besides that in constructions 1, 2! outputs of each power circuit of radiators arranged in different points of the dielectric sheet, it is impossible to use one converter with one input for signals of two polarizations. In antenna construction 3! there is one input for receiving two polarizations, but it has power circuits sequence, and with aperture of D=20 it is practically impossible to use them in antennas intended for the direct reception of satellite television broadcasts within frequency band 5-7% and with the efficiency 60%.
This way these antennas have obvious limits for their use in satellite television systems due to their narrow-band and bad elliptic.
The closest prior art to the proposed technical decision is a planar antenna array used for reception of satellite television broadcasts with two linear polarizations with a dielectric cover and two line sheets arranged with observance of definite distance, with a plurality of radiating apertures; two thin dielectric sheets--with power circuit for receiving signals of one (vertical) linear polarization on one of them and with power circuit for receiving signals of the other (horizontal) linear polarization on the other sheet; screen layer; power circuits; including exciter elements connected electromagnetically with radiating apertures on a conductive layer, power splitting elements and output probes connected with one waveguide output. With presence of low-noise converter with electronic polarization switcher connected through round input waveguide with antenna: with feed to converter one voltage--receiving of signal of one polarization available, with feed to converter another voltage receiving of cross polarization available 4!. But for this construction is obligatory: the presence of a metal plate with apertures dividing these sheets; four low dielectric insulators and many other references that arrange two dielectric sheets with intercross radiators and power circuits for these radiators between metal plates with apertures. Number of layers of such antennas together with protective cover, case, dielectric plates with power circuits, line plates with apertures, screen plates and so on is not less than 8-10. Besides that in order to escape diffraction petals of construction the radiator must be arranged on the distance not more than 0.9 I, where I is the length of wave in free space. And with aperture of antenna of D=20 the number of power dividers from input to radiator is not less than 8, which leads to considerable losses. More than that, as far as dielectric plates are arranged on different distances from upper conductive layer with radiating apertures and from bottom screen layer with apertures--this way conditions for exciting of radiating aperture by exciter elements of one sheet will differ from conditions for exciting of cross polarization by exciter elements of another sheet and they will not correspond to optimum. It is most clearly seen while receiving signals of right or left circular polarization. Output sections will also be on different distances. For receiving circular polarization signals into antenna construction 11! may be inserted quadature hybrid junctions that mast be arranged whether on dielectric sheets directly which will demand to insert new constructive elements in power circuits, because dielectric sheets arranged on certain distance from each other; or on antenna output which will also demand new costructive elements and will provide difficulties with placing of uniform antenna output in the center of antenna array and may reduce the number of radiators. Besides that quadature hybrid junctions have losses up to 0.2 . . . 0.5 dB and, due to their frequency independence, they may limit frequency band of antenna array with circular polarization.
The problem addressed by the invention is that of producing planar antenna array used for receiving signals with different polarization, that will be simple, reliable, highly technological and cheap and at the same time which is highly efficient across a broad frequency band. The decision is reached by reducing the number of radiating elements, which are additional reflectors of back radiation antennas (BRA), and by possibly arranging two power circuits with parallel feeding systems of exciter elements on one surfaces of one dielectric sheet with presence of one uniform output. The usage of BRA with the distances 2-3 between the centers of exciter elements makes conducting more simple and reduces the number of T-branches; it also obtains universal power circuit for different polarization signals that produces a whole number of variants of flat antenna with different parameters which differs only by the form of executing of exciter elements for circular or linear polarization. The aim is reached by the fact that in planar antenna array with different polarization containing arranged on definite distances protective dielectric cover, line plate with a plurality of radiating apertures, dielectric sheet and screen layer, exciter elements with output for signals of different polarization accordingly, two power circuits for the reception/transmission of signals of different polarization including feeding elements and output probes arranged in uniform waveguide output in the center of antenna array, on the inner surface of protective dielectric cover reflection elements array is arranged that are placed accordingly under the radiating apertures of line plate. The dielectric plate is located between screen layer and line plate-exciter elements with output for different polarization signals and two power circuits for the reception/transmission of different polarization signals arranged on one surface of dielectric sheet without intersection of conductors, and each of them has a pair of output probes arranged in such a way on plane of output waveguide cross-section that axes of each pair of output probes are perpendicular, and waveguide center is an axis of symmetry for output probes, half of exciter elements is connected to corresponding probes of pairs of output probes of power circuit and other half of exciter elements is connected to another corresponding probes of pairs of output probes corresponding power circuit. Exciter elements of power circuits are executed as circular polarization elements with outputs corresponding to left and right circular polarization, pairs of interaxes output probes intended for reception/transmission of right and left circular polarization accordingly; probes of waveguide cross-section arranged on the line bisecting between output probes intended for reception/transmission of linear polarization, and all the other probes--for reception/transmission of elliptical polarization with elliptic coefficient from 0 up to 1. Particularly, it is preferable to execute circular polarization elements as a pair of cross-probes, a loop arranged diagonal to them and galvanically connected with them, and a line which must be located not farther than 2/10 of wave length from the point of cross-probes' axis intersection and perpendicular to diagonal loop. Exciter elements may also be executed as to cross-probes, here the pair of interaxes of output probes will be intended for reception/transmission of vertical and horizontal polarization signals. It is worth-while that each reflection element of the array (which can be considered as additional reflector of each back radiation antenna) on the inner surface of protective dielectric sheet will be executed as a group of symmetrical rectangular conductive layer. It is more preferable that protective dielectric cover will be situated on the distance of 0.4-0.6 of wave length from the surface of the conductive layer with the plurality of radiating apertures. It is more preferable to execute screen layer with hollows disposed under radiating apertures of the conductive layer. It is worth-while to execute on outer surface of the conductive layer inner surface of protective dielectric cover accordingly borders and conductor lines that will divide these surfaces into cells, centers of these cells will correspond to centers of corresponding radiating apertures--and each reflection element on the inner surface of protective dielectric cover is placed in corresponding cells on this surface. It is worth-while to execute in the corner of each cell on conductive layer projections of geometrical figures, e. g.--9 squares, triangles, sectors, circles and so on.
Fulfillment of two power supply systems on one surface is known one dielectric payment without crossings in antenna with two polarizations 2, 3, 4, 5, 13, 14, 15!. However in a design 2, 3, 13, 14, 15! the outputs of each system are located in different places of sheet, that makes it impossible application of one converter with a general input for signals of two polarizations. In designs 4, 5, 13! the power supply systems are provided with a consecutive feed 15 stimulating elements, that excludes their use in antennas for direct reception of satellite TV--in frequency range 5-7% and with efficiency 60%.
The items of information on popularity of distinctive attributes, concerning applications of an array of reflecting elements on inner surfaces of a protective dielectric cover, located accordingly above radiating apertures of a conducting plate, and fulfillment of two power supply systems simultaneously for various polarizations (elliptic, two circular and/or two linear) on one surface of one dielectric sheet with parallel feed of stimulating elements at a general output, placed in the central part of array, is not available.